Edetate Calcium Disodium

Edetate calcium disodium (sodium calcium edetate) is a parenteral chelator for inorganic lead poisoning. It is administered intravenously or intramuscularly because oral absorption is poor. The antidote distributes predominantly extracellularly, does not cross the blood-brain barrier significantly, and is not metabolized, with an elimination half-life under 60 minutes. It chelates lead by displacing the central calcium ion with Pb²⁺. The primary source of mobilized lead is bone, with additional contributions from kidney and liver. Experimental studies show edetate calcium disodium is more effective than succimer in reducing bone lead concentrations. The antidote resolves symptoms of moderate to severe lead toxicity rapidly and has greater clinical experience, particularly in treating lead encephalopathy.

Calcium disodium edetate (EDTA-Na₂Ca) has strong antifungal activity against Penicillium digitatum, the cause of citrus green mold. The minimum inhibitory and fungicidal concentration against the P44 strain is 50 mmol L⁻¹. EDTA-Na₂Ca inhibits the fungus both in vitro and in vivo, with the latter involving enhancement of the host defense system. Treated P. digitatum showed delayed conidial germination, expanded hyphal tips, thickened septa and cell walls, and damaged mitochondria. Transcriptome and qRT-PCR analyses revealed that EDTA-Na₂Ca primarily disrupts carbohydrate metabolism, specifically pyruvate synthesis in glycolysis. The antifungal effects could be reversed by exogenous Mn²⁺, indicating that Mn²⁺ chelation is a key mechanism of action.